/*
 * Copyright (C) 2005-2011 MaNGOS <http://getmangos.com/>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef _PATH_GENERATOR_H
#define _PATH_GENERATOR_H

#include "SharedDefines.h"
#include "MoveSplineInitArgs.h"

class Unit;

// 74*4.0f=296y  number_of_points*interval = max_path_len
// this is way more than actual evade range
// I think we can safely cut those down even more
#define MAX_PATH_LENGTH         74
#define MAX_POINT_PATH_LENGTH   74

#define SMOOTH_PATH_STEP_SIZE   4.0f
#define SMOOTH_PATH_SLOP        0.3f

#define VERTEX_SIZE       3
#define INVALID_POLYREF   0

enum PathType
{
    PATHFIND_BLANK          = 0x00,   // path not built yet
    PATHFIND_NORMAL         = 0x01,   // normal path
    PATHFIND_SHORTCUT       = 0x02,   // travel through obstacles, terrain, air, etc (old behavior)
    PATHFIND_INCOMPLETE     = 0x04,   // we have partial path to follow - getting closer to target
    PATHFIND_NOPATH         = 0x08,   // no valid path at all or error in generating one
    PATHFIND_NOT_USING_PATH = 0x10,   // used when we are either flying/swiming or on map w/o mmaps
    PATHFIND_SHORT          = 0x20,   // path is longer or equal to its limited path length
};

class PathGenerator
{
public:
    explicit PathGenerator(Unit const* owner);

    // Calculate the path from owner to given destination
    // return: true if new path was calculated, false otherwise (no change needed)
    bool CalculatePath(float destX, float destY, float destZ, bool forceDest = false);

    // result getters
    G3D::Vector3 const& GetStartPosition() const { return _startPosition; }
    G3D::Vector3 const& GetEndPosition() const { return _endPosition; }
    G3D::Vector3 const& GetActualEndPosition() const { return _actualEndPosition; }

    Movement::PointsArray const& GetPath() const { return _pathPoints; }

    PathType GetPathType() const { return _type; }

private:
    Movement::PointsArray _pathPoints;  // our actual (x,y,z) path to the target
    PathType _type;                     // tells what kind of path this is

    G3D::Vector3 _startPosition;        // {x, y, z} of current location
    G3D::Vector3 _endPosition;          // {x, y, z} of the destination
    G3D::Vector3 _actualEndPosition;    // {x, y, z} of the closest possible point to given destination

    Unit const *_sourceUnit;          // the unit that is moving

    void SetStartPosition(G3D::Vector3 const& point) { _startPosition = point; }
    void SetEndPosition(G3D::Vector3 const& point) { _actualEndPosition = point; _endPosition = point; }
    void SetActualEndPosition(G3D::Vector3 const& point) { _actualEndPosition = point; }
    void NormalizePath();

    void Clear()
    {
        _pathPoints.clear();
    }

    void BuildShortcut();
};

#endif
